Effects of the yield criterion on local deformations in numerical simulation of profile forming

Three anisotropic plasticity models are implemented in LS-DYNA3D for shell analysis using backward Euler integration algorithms. The models have different yield criteria (Hill, Barlat and Lian, and Karafillis and Boyce) but have all associated flow rules and non-linear isotropic strain hardening. The anisotropic models are applied in finite element analysis of a stretch bending process for aluminium extrusions. In addition, simulations with the von Mises yield criterion and a non-quadratic yield criterion for isotropic materials are carried out. Plastic anisotropy and the shape of the yield surface are found to have significant effect on the local deformations predicted in the simulations. (C) 1998 Elsevier Science S.A. All rights reserved.